People waste less food if told of harm to environment

A piece of advice for green-minded restaurants and food service businesses — hide that compost bin.

That's because when diners know their scraps will be composted, they end up wasting more food, according to new research from Ohio State University.

“Do it, but just don’t brag about it,” said Danyi Qi, an agricultural economics researcher at OSU who co-led the study, which is under peer review.

On the flip side, consumers will minimize their leftovers after learning about shrinking landfill space and greenhouse-gas emissions related to food waste, the study also found.

The results suggest two prominent methods for reducing food waste — education and diverting from landfills — can counteract each other.

“The question is can they work in harmony, or do they work in conflict?” Qi said.

Food makes up about a fifth of the nation’s waste stream and winds up in landfills and incinerators more than any other single household trash material, according to the EPA. In 2015, the U.S. government set a goal to slash food loss in half.

Since that benchmark announcement, policymakers and businesses have doubled down on food-waste awareness campaigns, composting programs and efforts to donate leftovers to food banks, said Brian Roe, an agricultural, environmental and development economics professor and co-leader of the recent study.

“People are energized and putting together all these ideas,” Roe said. “It’ll have to be a multi-prong approach. The big issue is … to make sure they don’t crowd each other out.”

For the experiment, Roe and Qi allowed subjects to serve themselves from a buffet of sandwiches, chips and apple slices. Half were told their leftovers would be composted and the rest were informed their scraps would be sent to a landfill.

Researchers found that participants who were given information cards about the harm related to food waste were almost 40 percent more likely to clean their plates — unless they also were told their uneaten food would be composted. Then, the benefits of awareness vanished.

It’s possible that when people know their leftovers are destined for composting, they feel less guilty and freer to waste more, Qi said.

It could also be that once people have taken a single positive step toward reducing their environmental impact, they’re less motivated to take another, Roe said.

“Once one box has been checked, there’s not much appetite to do another thing,” Roe said. “Maybe for some people, that box has been checked off (with composting).”

Roe said little research has explored how different food-waste campaigns interact. The experiment conducted last summer suggests that simultaneous policies could have a lower total benefit, he said.

So really cutting down on food waste — the most destructive type of household waste in terms of greenhouse-gas emissions — could require toying with psychology.

In a previous research effort, Roe and Qi teamed up to conduct the first large-scale consumer survey of Americans’ attitudes on food waste.

They found that while more than three in four respondents said they feel guilty throwing away food, little more than half indicated they understood it was an environmental problem.

“We all cringe a bit if we bought that nice fish for a high price and we don’t end up eating it,” Roe said. “But people think of food as being natural — it’s not like throwing away a battery or something toxic.”

There is a hierarchy for reducing food waste, Qi said.

If properly done, the average family of four could save about $1,600 annually on tossed leftovers.

The first and simplest step is to buy less by making a list and inventorying your pantry before heading to the grocery store, Roe said.

Another option is to donate wholesome, edible food to local food banks, soup kitchens, pantries and shelters. In 2015, 13 percent of American households struggled to provide enough food for all their members, according to the U.S. Department of Agriculture.

A final way to reroute leftovers from the landfill is by composting.

Combining and curing organic waste like food scraps and yard trimmings in the proper ratios creates a product that can be used to help improve soils and feed backyard gardens.